<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <!-- 不同的循环子字符串 -->
    <script>
      var distinctEchoSubstrings = function (text) {
        const len = text.length
        let sum = 0
        let arr = []
        for (let i = 0; i < len; i++) {
          if (i + 1 > len / 2) {
            break
          }
          for (let j = 0; j < len; j++) {
            if (text.slice(j, j + (i + 1)) === text.slice(j + (i + 1), j + 2 * (i + 1))) {
              if (arr.indexOf(text.slice(j, j + (i + 1))) === -1) {
                arr.push(text.slice(j, j + (i + 1)))
                sum++
              }
            }
          }
        }
        return sum
      }
      console.log(distinctEchoSubstrings('abcabcabc'))
    </script>
  </body>
</html>
